Duplo-produto e variação da frequência cardíaca após esforço isocinético em adultos e idosos

Abstract

Introduction: Aging predisposes to multisystem changes, for example, in the cardiovascular and musculoskeletal systems. The practice of physical exercise is an important therapeutic resource to delay losses of organic functions. However, there is little knowledge about cardiovascular responses during and after isokinetic exercise in the elderly. Objective: The objective of this study is to analyze the responses of heart rate, blood pressure, and rate-pressure product in individuals of different age groups submitted to isokinetic muscular effort. Method: The study consisted of 60 volunteers distributed into three age groups – G1: 30–45 years, G2: 45–60 years, and G3: 60–75 years – submitted to bilateral flexion-extension knee test in isokinetic dynamometer with angular velocity of 60°/second to verify hemodynamic responses. Data were analyzed using the Bioestat® 5.3 software, by the Kruskal-Wallis test followed by Dunn’s test for independent samples and Friedman’s test for dependent samples, as well as comparing the Kaplan-Meier curves by means of log-rank test, considering P≤0.05. Results: The elderly group (G3) presented higher values of systolic blood pressure, rate-pressure product, and time to return to baseline heart rate compared to the younger group (G1). Conclusion: The 60–75 year old group had higher myocardial oxygen consumption during and after the exercise, as well as longer time to return to baseline HR compared with younger patients.